Lightning includes electrical discharges within a cloud, intracloud (IC) discharges, and cloud to ground (CG) discharges. Lightning occurs when electrical fields within a cloud intensify as particles of opposite polarity collect at differing regions within the cloud. Lightning begins with an initial electrical breakdown (i.e., a pulse) followed by leader channels from which a series of channel branches grow within a cloud forming a comprehensive branch channel structure. For IC lightning, the channel structure remains within the cloud. A CG discharge occurs when one or more branches extend from a cloud to the ground.
An increase in lightning activity often precedes even more severe weather phenomena, such as severe storms, tornadoes, hail, damaging downburst winds and potentially deadly cloud-to-ground lightning strikes. In addition, such lightning activity frequently occurs in localized clusters, also called cells. Lightning cells exhibit certain characteristics (e.g., lightning rate, IC/CG ratio) that are indicative of the potential for severe weather. Also, using detection methods and systems, data associated with lightning cells can be obtained and analyzed to determine the location and movement of specific cells across a geographic region.
Accurate and efficient detection of early lightning activity, such as the weaker, initial IC discharges, is critical for advanced forecasting of severe weather phenomena. Integrated detection of both IC lightning and CG lightning provides highly advanced predictive capabilities for characterizing severe storm precursors, improving lead times and comprehensive weather management planning. Numerous lightning detection systems and methods have been developed, each striving to determine the location, movement, frequency and intensity of lightning activity with better accuracy. Examples of such systems include the U.S. Precision Lightning Network (USPLN), the National Lightning Detection Network (NLDN) and the WeatherBug Total Lightning Network (WTLN).
Previous weather alert systems have relied on human intervention to determine the extent of severe weather activity and to initiate the notification of remote devices configured to receive alerts (e.g., through use of a display where a person evaluates weather data and select devices to receive the alerts). To increase the speed and accuracy of weather alert systems, it is desirable to eliminate the need for manual processing of severe weather data and issuance of alert messages.